/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.tsfile.read.common.block.column;

import org.apache.iotdb.tsfile.exception.write.UnSupportedDataTypeException;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.utils.TsPrimitiveType;
import org.openjdk.jol.info.ClassLayout;

import java.util.Arrays;

import static io.airlift.slice.SizeOf.sizeOf;
import static java.lang.Math.max;
import static org.apache.iotdb.tsfile.read.common.block.column.ColumnUtil.calculateBlockResetSize;

public class FloatColumnBuilder implements ColumnBuilder {

    private static final int INSTANCE_SIZE =
            ClassLayout.parseClass(FloatColumnBuilder.class).instanceSize();
    public static final FloatColumn NULL_VALUE_BLOCK =
            new FloatColumn(0, 1, new boolean[]{true}, new float[1]);

    private final ColumnBuilderStatus columnBuilderStatus;
    private boolean initialized;
    private final int initialEntryCount;

    private int positionCount;
    private boolean hasNullValue;
    private boolean hasNonNullValue;

    // it is assumed that these arrays are the same length
    private boolean[] valueIsNull = new boolean[0];
    private float[] values = new float[0];

    private long retainedSizeInBytes;

    public FloatColumnBuilder(ColumnBuilderStatus columnBuilderStatus, int expectedEntries) {
        this.columnBuilderStatus = columnBuilderStatus;
        this.initialEntryCount = max(expectedEntries, 1);

        updateDataSize();
    }

    @Override
    public ColumnBuilder writeFloat(float value) {
        if (values.length <= positionCount) {
            growCapacity();
        }

        values[positionCount] = value;

        hasNonNullValue = true;
        positionCount++;
        if (columnBuilderStatus != null) {
            columnBuilderStatus.addBytes(FloatColumn.SIZE_IN_BYTES_PER_POSITION);
        }
        return this;
    }

    @Override
    public ColumnBuilder writeTsPrimitiveType(TsPrimitiveType value) {
        return writeFloat(value.getFloat());
    }

    /**
     * Write an Object to the current entry, which should be the Float type;
     */
    @Override
    public ColumnBuilder writeObject(Object value) {
        if (value instanceof Float) {
            writeFloat((Float) value);
            return this;
        }
        throw new UnSupportedDataTypeException("FloatColumn only support Float data type");
    }

    @Override
    public ColumnBuilder write(Column column, int index) {
        return writeFloat(column.getFloat(index));
    }

    @Override
    public ColumnBuilder appendNull() {
        if (values.length <= positionCount) {
            growCapacity();
        }

        valueIsNull[positionCount] = true;

        hasNullValue = true;
        positionCount++;
        if (columnBuilderStatus != null) {
            columnBuilderStatus.addBytes(FloatColumn.SIZE_IN_BYTES_PER_POSITION);
        }
        return this;
    }

    @Override
    public Column build() {
        if (!hasNonNullValue) {
            return new RunLengthEncodedColumn(NULL_VALUE_BLOCK, positionCount);
        }
        return new FloatColumn(0, positionCount, hasNullValue ? valueIsNull : null, values);
    }

    @Override
    public TSDataType getDataType() {
        return TSDataType.FLOAT;
    }

    @Override
    public long getRetainedSizeInBytes() {
        return retainedSizeInBytes;
    }

    @Override
    public ColumnBuilder newColumnBuilderLike(ColumnBuilderStatus columnBuilderStatus) {
        return new FloatColumnBuilder(columnBuilderStatus, calculateBlockResetSize(positionCount));
    }

    private void growCapacity() {
        int newSize;
        if (initialized) {
            newSize = ColumnUtil.calculateNewArraySize(values.length);
        } else {
            newSize = initialEntryCount;
            initialized = true;
        }

        valueIsNull = Arrays.copyOf(valueIsNull, newSize);
        values = Arrays.copyOf(values, newSize);
        updateDataSize();
    }

    private void updateDataSize() {
        retainedSizeInBytes = INSTANCE_SIZE + sizeOf(valueIsNull) + sizeOf(values);
        if (columnBuilderStatus != null) {
            retainedSizeInBytes += ColumnBuilderStatus.INSTANCE_SIZE;
        }
    }
}
